1. Field of the Invention
The present invention relates to a tape with snap fastener in which the snap fastener made of thermoplastic synthetic resin material is fixed to front and rear surfaces of a tape or the like by integral molding. More particularly, the present invention relates to a tape with snap fastener in which the snap fastener is molded integrally on the front and rear surfaces of a tape or the like by penetration of synthetic resin material due to injection pressure at the time of injection molding without forming a fastener attaching hole in the tape or the like.
2. Description of the Prior Art
Conventionally, tapes with snap fasteners made of thermoplastic synthetic resin material have been used generally as disclosed in, for example, Japanese Patent Application Laid-Open Nos. 55-2469 and 62-155805. According to a manufacturing methods thereof, a hole is preliminarily made in a fastener attaching portion of a tape in order to fix the tape and the fastener firmly. Then, a cavity in the front and rear surfaces is charged with molten resin material through the hole so as to integrally mold a snap fastener of a desired configuration.
According to the above-described Japanese Patent Application Laid-Open No. 62-155805, in order to prevent a section around the tape attaching hole from being waved largely or deflected upon molding of the snap fastener, the section around the tape attaching hole is nipped with plural tape fixing pins protruding from an inner face of each cavity at a portion in which the section around the tape attaching hole is inserted within the cavity of each of upper and lower molds and then, molten resin material is injected so as to mold a fastener integrally on the section around the tape attaching hole.
However, as described above, formation of the fastener attaching hole in the tape and the tape fixing pins in the cavity is troublesome, and particularly formation of the attaching hole causes increase in forming processes, thereby increasing production cost. To avoid this problem, for example, Japanese Utility Model Application Laid-Open No. 56-16311 and Japanese Patent Application Laid-Open Nos. 10-33211 and 2001-149117 have disclosed such a method which employs a tape having large gaps and in which the fastener is molded integrally on the tape by filling the cavities on the front and rear sides with molten resin material through the gaps without forming the fastener attaching hole in the tape and the tape fixing pins in a mold cavity.
Further, the male fastener disclosed in the above-described Japanese Patent Application Laid-Open No. 2001-149117 has a bottomed cylindrical shape, thereby leading to reduction of material cost. Forming the male fastener in a bottomed cylindrical shape, which is produced by cutting out a flange portion from the male fastener, means that the entire thickness of the male fastener in its appearance, i.e., the amount of protrusion of the male engaging protrusion which projects from the tape surface, can be reduced without changing the protrusion height of the male engaging protrusion from the tape surface. Moreover, according to this publication, no resin is disposed in the center of the bottom portion of the male fastener so that the tape is exposed inside and outside the bottom portion. This is probably for reducing material cost further.
The male fastener disclosed in the above-described Japanese Patent Application Laid-Open No. 2001-149117 merely has the bottomed cylindrical shape with no flange portion at its bottom and the outside diameter of the engaging protrusion projecting from the tape is substantially equal to an inner diameter of an engaging/disengaging opening edge of a mating female fastener, which receives the male fastener. On the other hand, the mating female fastener presents an ashbowl shape without any flange portion. Thus, in the fastener comprising a pair of male and female parts as described in this publication, the outer diameter of the female fastener is larger than the outside diameter of the male fastener.
Consequently, as shown in FIG. 6 and FIGS. 12(D) and 12(E) of this publication, when the male and female fasteners are engaged with each other, the female fastener comes into contact with the tape surface of the male fastener side. As a result, the tape tends to be damaged by excessive rubbings due to frequent engaging/disengaging operations.
The shape of the male fastener of the same publication is a simple circle having the same outer diameter as that of the male engaging protrusion in which the shape at the bottom on an opposite side to the engaging protrusion is substantially cylindrical. The outer surface of the male fastener does not allow anything but a mere concave portion to be formed in its center portion. Therefore, improvement from the design aspect is limited, so that this male fastener is inferior to a metallic fastener in terms of its appearance.
Moreover, according to the same publication, if a ring-like expanded portion is formed on an opening edge inner face of the engaging protrusion of the male fastener, the inner face of the engaging protrusion can be used as an engaging/disengaging portion of the female fastener. In this case, as described above, it is troublesome to find out a combination of male and female counterparts which can engage with or disengages from each other from many kinds of fasteners having a simple external surface and configuration. In addition, when the same fastener is attached to clothing, it is difficult to distinguish the male fastener from the female fastener and the male fastener or the female fastener may be mistaken for another.
The present invention has been achieved to solve the problems described above. An object of the invention is to provide a tape with snap fastener in which the fastener is molded thinly and integrally on the tape and which allows the male and female fastener tapes to be selected easily when they are attached to a clothing and eliminates a possibility that the fastener may contact directly the tape when the male and female fasteners are engaged with or disengaged from each other, thereby ensuring an excellent durability and external design performance.
The above-described problems are solved by a tape with snap fastener according to the basic structure of the present invention, in which at least one male or female synthetic resin snap fastener is molded integrally on the tape, wherein the snap fastener comprises a base portion to be fixed to the front and rear surfaces of the tape and an engaging protruding portion projecting vertically from the base portion. The engaging protruding portion is substantially cylindrical. A ring-like continuous concave groove portion having the same center as the base portion and an inner diameter exceeding the inner diameter of the engaging protruding portion, is provided on any one of front and rear surfaces of the base portion. The engaging protruding portion and the continuous concave groove portion have a depth reaching the tape.
In the snap fastener of this kind, the male fastener comprises the base portion to be fixed to the front and rear surfaces of the tape and the engaging protruding portion projecting from the base portion over a tape face. The male fastener has an expanded portion which engages with or disengages from a female fastener, the expanded portion being provided on the peripheral face of a top end of the engaging protruding portion. Usually, the base portion has a flange portion longer in the diameter direction than the engaging protruding portion. On the other hand, as in the male fastener, the female fastener comprises the base portion to be fixed on the front and rear surfaces of the tape and the engaging protruding portion projecting from the base portion over a tape face. The engaging protruding portion is cylindrical and has a ring-like expanded portion which engages with or disengages from the male fastener, the expanded portion being provided along an opening edge inner face.
According to the present invention, the engaging protruding portion of the male fastener is also formed cylindrically like the engaging protruding portion of the female fastener. The cylindrical shape mentioned here includes a case where the cylinder is divided to two or more sections across a flat plane passing its axis line. Further, according to the present invention, the ring-like concave groove portion having the inner diameter exceeding the inner diameter of the engaging protruding portion is formed around the center of the base portion in any one of front and rear of the base portion. Thus, when the male fastener is molded, a portion corresponding to the bottom face of the cylindrical engaging protruding portion and a tape portion corresponding to the ring-like continuous concave groove portion are supported by parts of a metal mold.
When the ring-like continuous concave groove portion is formed on the surface of the base portion on the protrusion side of the engaging protruding portion, a gate portion, which serves as a molten resin introduction port into a cavity, can be disposed in the center of the base portion of the fastener. Therefore, resin pressure applied to the tape is received by a portion corresponding to the bottom face of the engaging protruding portion and a portion corresponding to the ring-like continuous concave groove portion. Consequently, swing of the tape is eliminated so that molten resin can be filled fully into the cavity. Further, if the ring-like continuous concave groove portion is formed on the surface of the base portion on an opposite side to the protrusion side of the engaging protruding portion, the resin pressure in the cavity is received by deflected portions of the front and rear surfaces of the tape. Consequently, the swing of the tape is suppressed, and molten resin can be filled fully in the cavity. Further, because the surface of the base portion of the fastener is not a mere flat plane, the appearance performance thereof is improved.
According to the present invention, preferably, the ring-like continuous concave groove portion is circular or polygonal. Although the polygonal mentioned here includes ordinary polygons consisting of straight lines such as a regular polygon and a star shape, ring-like shapes obtained by connecting adjacent vertexes of a polygon with curved lines having diversified curvatures are also included. According to the present invention, forming the ring-like concave groove portion having such diversified shapes enriches the appearance performance of the snap fastener. In the meantime, although the aforementioned continuous concave groove portion may be a single ring, it may be formed in multiple-ring form around the same center.
The ring-like continuous concave groove portion may be formed around a base end of the engaging protruding portion or on the surface on an opposite side to the protruding side of the engaging protruding portion. When the ring-like concave groove portion is formed around the base end of the engaging protruding portion, upon engagement of the male fastener with the mating female, the female fastener comes into contact with the base portion so as to engage with the male fastener, and it never contacts the tape. Therefore, the tape is free of damage by abrasion even if the engagement/disengagement of the fastener is repeated, thereby securing durability. Also, when the ring-like continuous concave groove portion is formed on a surface of the base portion on an opposite side to the protrusion side of the engaging protruding portion, upon engagement of the fasteners, the ring-like continuous concave groove portion is exposed on the surface of a fastener attaching object material. Thus, disharmony feeling about the appearance design thereof is eliminated unlike a mere flat plane or ring-like fastener.
According to the present invention, it is preferable that, as in the continuous concave, plural hollow portions, having a depth reaching the tape groove and arranged intermittently in a ring form, are provided on the surface on an opposite side to the base portion corresponding to the ring-like continuous concave groove portion. With such a configuration, when the male fastener is molded, the tape is nipped and supported at plural faces by a bore forming protrusion in the engaging protruding portion projecting into the cavity, a ring-like protrusion for forming the ring-like concave groove portion, and plural protrusions for forming concave portions, so that swing or moving of the tape is eliminated. Consequently, a tape with male fasteners having a more stabilized configuration and structure is manufactured. Further, forming the configuration of the hollow portion into a shape having a design performance improves its appearance.
Preferably, the tape consists of woven or knitted fabric, and weaving patterns or stitches having gaps large enough for molten resin to pass through are formed at least at a fastener attaching portion thereof. Molten resin passes through the gaps smoothly so that it is filled in the cavity uniformly upon molding of the male fastener. Accordingly, no special fastener attaching hole has to be formed in the tape, so that a base having a stable structure is formed on both the front and rear surfaces of the tape.